Dear hobbyist, there are some people who disagree,but what I use is Kent Marine Garlic .It comes in a bottle and is very strong. Others believe its better to use fresh garlic ,which can be quite messy after peeling,mashing,then applying the garlic to the fishes food . With the kent garlic,all you need to do is to use the dropper to apply the garlic to you fishes food,its that easy .